Work machine
A work machine includes a sensor that detects a retroreflective material and other objects in a distinguishable manner, a solenoid valve that restricts an operation signal outputted from an operation device, and a controller configured to control the solenoid valve based on the detection result. The controller controls the solenoid valve based on information concerning whether or not the object detected by the sensor is a retroreflective material and information concerning whether a position of the object detected by the sensor is in a first detection region at least partially including an operation range of a machine body or a second detection region located adjacent to and above the first detection region. This makes it possible to restrain contact between the work machine and an obstacle while restraining a reduction in a detection range due to exclusion of a structure of the work machine from an object of detection.
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The present invention relates to a work machine.
BACKGROUND ARTIn a work machine such as a hydraulic excavator, a technology of assisting operator's monitoring of the surroundings of the work machine by displaying an image obtained by a camera provided on a machine body on a monitor in a cab has been known.
As a technology concerning such monitoring of the surroundings of a work machine, for example, Patent Document 1 discloses a work vehicle surrounding monitor system in which a monitor region is set in the periphery of a work vehicle and the presence of a worker in the monitor region is detected. The work vehicle surrounding monitor system includes a regressive reflection material worn by the worker, and a surrounding monitor device that applies laser light in a scanning manner from the work vehicle toward the monitor region, receives laser light reflected by the regressive reflection material, and detects the presence of the worker based on a light reception level. The regressive reflection material includes a cube corner reflector in which a multiplicity of cube corner prisms are arranged. The surrounding monitor device includes a coaxial regressive-reflection type photoelectric sensor that applies non-diffused laser light, receives the reflective light substantially coaxially, and outputs a light reception level. A laser light source of the photoelectric sensor is pulse-driven at a predetermined cycle, and the presence of the worker is detected based on the received light pulse.
In addition, Patent Document 2 discloses a construction machine object detection system that detects an object present in the surroundings of a construction machine including an upper swing structure mounted on a lower track structure through a swing mechanism. The construction machine object detection system has an object detection section that detects an object based on an output of a scanning type distance measuring device attached to the upper swing structure. Light emitted from the scanning type distance measuring device passes through a gap between the upper swing structure and the lower track structure. Patent Document 3 discloses an operation restrictor for a construction machine including human detecting means for detecting a human on the basis of a plurality of predetermined ranges set based on front, rear, left, and right directions of the construction machine and a separate distance from the construction machine, selecting means for selecting contents of restriction for the corresponding one of the predetermined ranges in a case where a human is detected by the human detecting means, and restricting means for restricting an operation of the construction machine based on the restriction contents.
PRIOR ART DOCUMENT Patent Documents
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- Patent Document 1: JP-2005-032141-A
- Patent Document 2: JP-2015-229836-A
- Patent Document 3: JP-2014-218849-A
However, in the prior art described in Patent Document 1, though the worker can be detected by applying laser light in a scanning manner and detecting light reflected from a retroreflective material worn by the worker, other materials and obstacles that do not have a retroreflective material cannot be recognized. In addition, in the prior art described in Patent Document 2, a detection range in a vertical direction is restricted by a plane passing through the gap between the upper swing structure and the lower track structure, so that, although the lower track structure swung relative to the upper swing structure can be excluded from the object of detection, a worker or another obstacle located at a position below a lower surface of the upper swing structure cannot be detected. Therefore, for example, even when the technology of Patent Document 3 is applied, the operation of the work machine cannot be suitably restricted when detecting obstacles.
The present invention has been made in consideration of the foregoing. It is an object of the present invention to provide a work machine capable of restraining the contact between the work machine and an obstacle while restraining a reduction in detection range due to exclusion of a structure of the work machine from the object of detection.
Means for Solving the ProblemsWhile the present application includes a plurality of means for solving the above problem, one example thereof is a work machine including an actuator for driving a machine body, an operation device operated for driving the actuator, a sensor provided on the machine body for detecting objects present in surroundings of the machine body, a restrictor that restricts the driving of the actuator by the operation device, and a controller configured to control the restrictor based on a detection result of the sensor. The sensor is capable of detecting a specific object from among the objects in a distinguishable manner. The controller is configured to control, in a case where an object is detected by the sensor, the restrictor based on information concerning whether or not the object detected by the sensor is the specific object and information concerning whether a position of the object detected by the sensor is in a first detection region set so as to at least partially include an operation range of the machine body or a second detection region located adjacent to and above the first detection region.
Advantages of the InventionAccording to the present invention, the contact between the work machine and an obstacle can be restrained while restraining a reduction in detection range due to exclusion of a structure of the work machine from the object of detection.
An embodiment of the present invention will be described below referring to
In
The front work implement 3 is configured by coupling a plurality of driven members (a boom 3a, an arm 3b, and a bucket 3c) each rotated vertically. A base end of the boom 3a is rotatably supported on a front portion of the upper swing structure 2. In addition, one end of the arm 3b is rotatably coupled to a tip end of the boom 3a, and the bucket 3c is rotatably coupled to the other end (tip end) of the arm 3b. The boom 3a, the arm 3b, and the bucket 3c are respectively driven by a boom cylinder 3d, an arm cylinder 3e, and a bucket cylinder 3f which are hydraulic actuators.
The lower track structure 1 includes a pair of crawlers 1e and 1f respectively wrapped around a pair of left and right crawler frames 1c and 1d, and track hydraulic motors 1a and 1b as hydraulic actuators for driving the respective crawlers 1e and 1f through speed reduction mechanisms and the like. Note that, in
The upper swing structure 2 includes each member disposed on a swing frame serving as a base, and the swing frame is driven to swing relative to the lower track structure 1 by a swing hydraulic motor 10 which is a hydraulic actuator, whereby the upper swing structure 2 can swing relative to the lower track structure 1.
On a front side of the swing frame of the upper swing structure 2, a cab 4 on which an operator rides to operate the hydraulic excavator 100 is disposed; in addition, an engine 25 as a prime mover, a hydraulic pump 26 and a pilot pump 27 driven by the engine 25, and a hydraulic circuit system for driving hydraulic actuators (the track hydraulic motors 1a and 1b, the swing hydraulic motor 10, the boom cylinder 3d, the arm cylinder 3e, the bucket cylinder 3f) are mounted (see
As illustrated in
A plurality of sensors 14 to 16 for imaging the surroundings of the upper swing structure 2 are mounted on left and right sides and a rear side of an upper portion of the upper swing structure 2. The plurality of sensors 14 to 16 are respectively referred to as a right side sensor 14, a rear side sensor 15, and a left side sensor 16 according to the layout thereof. In other words, the plurality of sensors 14 to 16 include the left side sensor 16 which is provided on a rear side of the cab 4 on the left side of the upper swing structure 2 and a detection range of which includes the front side and the left side of the upper swing structure 2, the right side sensor 14 which is provided on the right side of the upper swing structure 2 and a detection range of which includes the front side and the right side of the upper swing structure 2, and the rear side sensor 15 which is provided on the rear side of the upper swing structure 2 and a detection range of which includes the left and right sides and the rear side of the upper swing structure 2.
In
The directional control valve 28 is of a center bypass type, and has a center bypass passage located on a center bypass line 28a. The center bypass passage is connected in series with the center bypass line 28a, the center bypass passage communicates with the center bypass line 28a when a spool of the directional control valve 28 is in a neutral position, and the communication of the center bypass passage with the center bypass line 28a is interrupted when the spool of the directional control valve 28 is changed over to a changeover position on the left side or the right side in
The directional control valve 28 can be changed over by a pilot pressure (operation signal) from the operation device 4b. The operation device 4b has a pair of pilot valves that generate a pilot pressure with a delivery pressure of the pilot pump 27 as a source pressure, according to an operation amount. For example, when the operation device 4b is operated from the neutral position to a direction corresponding to a left swing (for example, the left side), a pilot pressure generated in one of the pilot valves according to the operation amount is outputted to a pressure receiving section on the right side in
Solenoid valves 23a and 23b are provided in respective lines from the operation device 4b to the two pressure receiving sections of the directional control valve 28. The solenoid valves 23a and 23b are restrictors that restrict a pilot pressure (operation signal) outputted from the operation device 4b to the directional control valve 28, and restrict the pilot pressure (operation signal) based on a solenoid valve current (command signal) from the controller 20 described later, to thereby restrict an operation velocity of the swing hydraulic motor which is a hydraulic actuator.
A pilot relief valve (not illustrated) that holds the delivery pressure of the pilot pump 27 constant is provided in a delivery line 27a of the pilot pump 27. In addition, a lock valve 27b is provided in the delivery line 27a of the pilot pump 27, and the lock valve 27b can be changed over according to an operation of the gate lock lever 4f. The gate lock lever 4f is provided with a position switch (not illustrated) which is put into a closed state when the gate lock lever 4f is in an unlocked position (lowered position) and which is put into an open state when the gate lock lever 4f is in a locked position (raised position). For example, when the position switch is put into the closed state, a solenoid section of the lock valve 27b is energized through the position switch, and the lock valve 27b is changed over to a communication position. As a result, the delivery line 27a of the pilot pump 27 is put into communication, and the delivery pressure of the pilot pump 27 is introduced to the operation device 4b and the like. As a result, a pilot pressure is generated by an operation of the operation device 4b or the like, and the hydraulic actuator can be caused to work (operable state). On the other hand, when the position switch is put into the open state, the lock valve 27b is put into an interrupting position. As a result, communication of the delivery line 27a of the pilot pump 27 is interrupted. Consequently, a pilot pressure is not generated even if the operation device 4b or the like is operated, and the hydraulic actuator is not caused to work (inoperable state).
Note that a hydraulic circuit system concerning the left and right track hydraulic motors 1a and 1b, the boom cylinder 3d, the arm cylinder 3e, and the bucket cylinder 3f which are not illustrated in
In addition, solenoid valves 24a and 24b are provided in respective lines from the operation devices 4d and 4e at least concerning a traveling operation to the two pressure receiving sections of the respective directional control valves (not illustrated) for the hydraulic motors 1a and 1b, and pilot pressures (operation signals) are restricted based on the solenoid valve currents (command signals) from the controller 20, whereby operation velocities of the track hydraulic motors 1a and 1b which are hydraulic actuators are restricted.
The hydraulic excavator 100 in the present embodiment configured as above has a surrounding monitor function that restricts operations of the hydraulic excavator 100 based on the detection results of the sensors 14 to 16.
In
The sensors 14 to 16 are sensors that detect distances and directions from the sensors 14 to 16 to an object and output a position of the detected object in a three-dimensional coordinate system as a detection result, and are, for example, infrared depth sensors. In addition, the sensors 14 to 16 are capable of detecting a retroreflective material and other members (objects) in a distinguishable manner, and output information concerning whether or not the object detected as a detection result is a retroreflective material.
In
The first detection region 30b and the second detection region 30a are each determined in terms of an object (member) as the object of detection by the sensor 14. Of a retroreflective material worn by a worker operating in the surroundings of the hydraulic excavator 100 and other objects, the first detection region 30b is a detection region whose detection object is only the retroreflective material. In addition, the second detection region 30a is a detection region whose detection object is both the retroreflective material and the other objects. In other words, the controller 20 has acquired information concerning the three-dimensional position of the detected object and information concerning the kind of the detected object (whether or not the detected object is the retroreflective material), as a detection result from the sensor 14. In a case where the three-dimensional position where an object is detected is in the first detection region 30b, it is determined that an object is detected only when the detected object is a retroreflective material. Even if an object other than the retroreflective material such as the lower track structure 1 is detected, it is determined that the detection of an object is absent. In addition, in a case where the three-dimensional position where an object is detected is in the second detection region 30a, the controller 20 determines that an object is detected no matter whether the detected object is a retroreflective material or another object.
The controller 20 has an object/retroreflective material determination section 20a and an operation restriction determination section 20b.
As depicted in
In addition, when the determination result in step S100 is YES and the sensor having detected an object is the right side sensor 14 or the left side sensor 16, it is determined whether the detected object includes a retroreflective material (step S110), a detection flag A is outputted to the operation restriction determination section 20b when the determination result is YES (step S111), whereas a detection flag B is outputted to the operation restriction determination section 20b when the determination result is NO (step S112), and the processing is finished.
In addition, when the determination result of step S100 is YES and the sensor having detected an object is the rear side sensor 15, it is determined whether or not the detected object includes a retroreflective material (step S120), a detection flag C is outputted to the operation restriction determination section 20b when the determination result is YES (step S121), whereas a detection flag D is outputted to the operation restriction determination section 20b when the determination result is NO (step S122), and the processing is finished.
Subsequently, the operation restriction determination section 20b determines what the detection flag outputted from the object/retroreflective material determination section 20a is (step S200). When the detection flag is determined to be A or C, the solenoid valve currents outputted to the solenoid valves 23a and 23b for swing and the solenoid valve currents outputted to the solenoid valves 24a and 24b for traveling are both made to be 100%, whereby a swing operation and a traveling operation are stopped (step S201), and the processing is finished. In other words, when it is considered that a worker wearing a retroreflective material is detected, both a swing operation and a traveling operation are stopped, whereby contact of the hydraulic excavator 100 with the worker can be prevented.
In addition, when it is determined that the detection flag is B in step S200, the solenoid valve currents outputted to the solenoid valves 23a and 23b for swing are set to 50%, whereas the solenoid valve currents outputted to the solenoid valves 24a and 24b for traveling are set to 100%, whereby the operation speed of a swing operation is decelerated and a traveling operation is stopped (step S202), and the processing is finished. In other words, when an object other than a retroreflective material (namely, an object other than a worker) is detected on a lateral side of the hydraulic excavator 100 (specifically, a lateral side of the upper swing structure 2), the swing speed is not stopped but is decelerated and the traveling operation is stopped, whereby the contact with the object detected on the lateral side can be suitably restrained while restraining a decrease in operating efficiency.
In addition, when it is detected that the detection flag is D in step S200, the solenoid valve currents outputted to the solenoid valves 23a and 23b for swing are set to 0 (zero) % and the solenoid valve currents outputted to the solenoid valves 24a and 24b for traveling are set to 100%, whereby the operation speed of a swing operation is not restricted and a traveling operation is stopped (step S203), and the processing is finished. In other words, when an object other than a retroreflective material (namely, an object other than a worker) is detected on the rear side of the hydraulic excavator 100 (specifically, on the rear side of the upper swing structure 2), the swing speed is maintained and a traveling operation is stopped, whereby the contact with the object detected on the rear side can be suitably restrained while restraining a decrease in operating efficiency.
Effects of the present embodiment configured as above will be described.
In a conventional technology of detecting a worker by applying laser light in a scanning manner and detecting light reflected from a retroreflective material worn by the worker, other materials or obstacles not having a retroreflective material cannot be recognized. In addition, in a conventional technology in which the detection range in the vertical direction is restricted by a plane passing between the upper swing structure and the lower track structure, though the lower track structure swung relative to the upper swing structure can be excluded from the object of detection, a worker or other obstacles located at a position lower than the lower surface of the upper swing structure cannot be detected. Therefore, for example, even when the conventional technology of restricting an operation of a work machine in a case where an obstacle is detected is applied, the operation of the work machine cannot be suitably restricted when the obstacle is detected.
On the other hand, the present embodiment provides the hydraulic excavator 100 including the operating devices 4b to 4e that output operation signals for driving the track hydraulic motors 1a and 1b, the hydraulic cylinders 3d to 3f, and the swing hydraulic motor 10 which are hydraulic actuators, the sensors 14 to 16 capable of detecting a retroreflective material which is a specific object and other objects in a distinguishable manner, the solenoid valves 23a, 23b, 24a, and 24b as restrictors that restrict driving of the hydraulic actuators by restricting operation signals outputted from the operation devices 4b to 4e, and the controller 20 configured to control the solenoid valves 23a, 23b, 24a, and 24b based on detection results of the sensors 14 to 16. In the hydraulic excavator 100, the controller 20 is configured to control, in a case where an object is detected by the sensors 14 to 16, the solenoid valves 23a, 23b, 24a, and 24b based on the information concerning whether or not the object (member) detected by the sensors 14 to 16 is a retroreflective material and the information concerning whether the position of the object (member) detected by the sensors 14 to 16 is in the first detection region 30b at least partially including the operation range of the machine body or the second detection region 30a adjacent to the first detection region 30b. Therefore, the contact of the hydraulic excavator 100 with an obstacle can be restrained while restraining a reduction in the detection range due to exclusion of the structure of the hydraulic excavator 100 from the object of detection.
Note that the setting of the detection regions is not limited to the one described referring to
The characteristic features of the present embodiment configured as above will be described.
(1) In the above embodiment, in the work machine (for example, the hydraulic excavator 100) including the actuators (for example, the track hydraulic motors 1a and 1b, the swing hydraulic motor 10) for driving the machine body (for example, the lower track structure 1 and the upper swing structure 2), the operation devices 4b to 4e operated for driving the actuators, the sensors 14 to 16 that are provided on the machine body and detect objects present in the surroundings of the machine body, the restrictors (for example, the solenoid valves 23a, 23b, 24a, and 24b) that restrict the driving of the actuators by the operation devices, and the controller 20 configured to control the restrictors based on detection results of the sensors, the sensors are capable of detecting a specific object from among the objects in a distinguishable manner, and the controller is configured to control, in a case where an object is detected by a sensor, the restrictors based on the information concerning whether or not the object detected by the sensor is the specific object and the information concerning whether the position of the object detected by the sensor is in the first detection region 30b set so as to at least partially include the operation range of the machine body or the second detection region 30a set so as to be adjacent to and above the first detection region.
As a result, the contact between the work machine and an obstacle can be restrained while restraining a reduction in the detection range due to exclusion of the structure of the work machine from the object of detection.
(2) In addition, in the above embodiment, in the work machine (for example, the hydraulic excavator 100) of (1) above, the controller 20 is configured to control the restrictors (for example, the solenoid valves 23a, 23b, 24a, and 24b) when the objects is detected in the second detection region and when the specific object is detected in the first detection region.
(3) Beside, in the above embodiment, in the work machine (for example, the hydraulic excavator 100) of (2) above, the controller 20 is configured not to perform control by the restrictors (for example, the solenoid valves 23a, 23b, 24a, and 24b) in a case where the objects is detected in the first detection region, the objects is not detected in the second detection region, and further the objects detected is not the specific object.
(4) In addition, in the above embodiment, in the work machine (for example, the hydraulic excavator 100) of (1) above, the sensors 14 to 16 are infrared depth sensors.
(5) Besides, in the above embodiment, in the work machine (for example, the hydraulic excavator 100) of (1) above, the specific object is a retroreflective material.
(6) In addition, in the above embodiment, in the work machine (for example, the hydraulic excavator 100) of (1) above, the machine body includes the upper swing structure 2 and the lower track structure 1, and the restrictors (for example, the solenoid valves 23a, 23b, 24a, and 24b) restrict at least either one of an traveling operation of the lower track structure and a swing operation of the upper swing structure relative to the lower track structure.
(7) Besides, in the above embodiment, in the work machine (for example, the hydraulic excavator 100) of (1) above, the machine body includes the upper swing structure 2 and the lower track structure 1, and at least a part of the boundary between the first detection region 30b and the second detection region 30a is set so as to be between the lower end of the upper swing structure and the upper end of the lower track structure.
ADDITIONAL REMARKNote that the present invention is not limited to the above-described embodiment, and includes various modifications and combinations within such a range as not to depart from the gist of the invention. In addition, the present invention is not limited to the one including all the configurations described in the above embodiment, and includes those in which some of the configurations are deleted. Besides, the above configurations, functions, and the like may be partly or entirely realized by, for example, designing in the form of an integrated circuit or the like. In addition, the above configurations, functions, and the like may be realized by software by a processor interpreting and executing programs for realizing the respective functions.
DESCRIPTION OF REFERENCE CHARACTERS
-
- 1: Lower track structure
- 1a, 1b: Track hydraulic motor
- 1c, 1d: Crawler frame
- 1e, 1f: Crawler
- 2: Upper swing structure
- 3: Front work implement
- 3a: Boom
- 3b: Arm
- 3c: Bucket
- 3d: Boom cylinder
- 3e: Arm cylinder
- 3f: Bucket cylinder
- 4: Cab
- 4a: Seat
- 4b to 4e: Operation device
- 4f: Gate lock lever
- 4g: Monitor
- 10: Swing hydraulic motor
- 14: Right side sensor
- 14: Sensor
- 15: Rear side sensor
- 15: Sensor
- 16: Left side sensor
- 16: Sensor
- 20: Controller
- 20a: Object/retroreflective material determination section
- 20b: Operation restriction determination section
- 23a, 23b: Solenoid valve
- 24a, 24b: Solenoid valve
- 25: Engine
- 26: Hydraulic pump
- 26a: Delivery line
- 27: Pilot pump
- 27a: Delivery line
- 27b: Lock valve
- 28: Directional control valve
- 28a: Center bypass line
- 30, 31: Detection range
- 30a, 31a: Second detection region
- 30b, 31b: First detection region
- 29a: tank line
- 100: Hydraulic excavator
Claims
1. A work machine comprising:
- an actuator for driving a machine body;
- an operation device operated for driving the actuator;
- a sensor provided on the machine body for detecting objects present in surroundings of the machine body;
- a restrictor that restricts the driving of the actuator by the operation device; and
- a controller configured to control the restrictor based on a detection result of the sensor,
- wherein the sensor is capable of detecting a specific object from among the objects sensor is configured to detect, and
- wherein a detection range of the sensor is set to include a first detection region that at least partially includes an operation range of the machine body and a second detection region located adjacent to and above the first detection region in a vertical direction of the machine body, and
- wherein the controller is configured to restrict, in a case where an object is detected in the first detection region by the sensor, the actuator by the restrictor only when the detected object is the specific object, and restrict, in a case where an object is detected in the second detection region by the sensor, the actuator by the restrictor even if the detected object is not the specific object.
2. The work machine according to claim 1,
- wherein the controller is configured not to perform control by the restrictor in a case where the objects are detected in the first detection region, the objects are not detected in the second detection region, and further the objects detected are not the specific object.
3. The work machine according to claim 1,
- wherein the sensor is an infrared depth sensor.
4. The work machine according to claim 1,
- wherein the specific object is a retroreflective material.
5. The work machine according to claim 1,
- wherein the machine body includes an upper swing structure and a lower track structure, and
- wherein the restrictor restricts at least one of a traveling operation of the lower track structure and a swing operation of the upper swing structure relative to the lower track structure.
6. The work machine according to claim 1,
- wherein the machine body includes an upper swing structure and a lower track structure, and
- wherein at least a part of a boundary between the first detection region and the second detection region is set so as to be between a lower end of the upper swing structure and an upper end of the lower track structure.
9113047 | August 18, 2015 | Onuma |
9598836 | March 21, 2017 | Hargrave, Jr. et al. |
9776566 | October 3, 2017 | Ishimoto |
9836938 | December 5, 2017 | Kiyota |
11697920 | July 11, 2023 | Kiyota |
20180245315 | August 30, 2018 | Kaiso et al. |
20180347147 | December 6, 2018 | Doi |
20200032489 | January 30, 2020 | Yamazaki |
108508888 | September 2018 | CN |
3604688 | February 2020 | EP |
07-011672 | January 1995 | JP |
2005-032141 | February 2005 | JP |
2005-180943 | July 2005 | JP |
2012-01995 | January 2012 | JP |
2014-218849 | November 2014 | JP |
2015-168973 | September 2015 | JP |
2015-229836 | December 2015 | JP |
2018-62412 | April 2018 | JP |
2019-039206 | March 2019 | JP |
2012/053105 | April 2012 | WO |
- Japanese Office Action received in corresponding Japanese Application No. 2019-086384 dated Sep. 13, 2022.
- International Preliminary Report on Patentability received in corresponding International Application No. PCT/JP2020/017246 dated Nov. 4, 2021.
- International Search Report of PCT/JP2020/017246 dated Jul. 7, 2020.
- Chinese Office Action received in corresponding Chinese Application No. 202080014647.3 dated May 24, 2022.
- Extended European Search Report received in corresponding European Application No. 20796273.9 dated Oct. 25, 2022.
Type: Grant
Filed: Apr 21, 2020
Date of Patent: Jul 16, 2024
Patent Publication Number: 20220170244
Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD. (Tokyo)
Inventors: Naoki Hagiwara (Kasumigaura), Kazuhiko Mizoguchi (Ishioka), Keiichirou Anahara (Kasumigaura)
Primary Examiner: Russell Frejd
Assistant Examiner: Brandon Z Willis
Application Number: 17/436,478
International Classification: E02F 9/26 (20060101); E02F 9/12 (20060101); E02F 9/20 (20060101); E02F 9/24 (20060101);